package chapter10;

import java.sql.*;

public class Example01 {
    public static void main(String[] args) throws SQLException {
        /**JDBC连接数据库
         * 1.加载驱动
         * 2.连接
         * 3.表结构——预处理（SQL）
         * 4.执行SQL语句
         * 5.结果
         * 6.释放 连接
         */

        Statement stmt = null;
        ResultSet rs = null;
        Connection conn = null;
        try {
            // 1.注册数据库的驱动
            Class.forName("com.mysql.cj.jdbc.Driver");
            // 2.通过DriverManager获取数据库连接
            String url = "jdbc:mysql://localhost:3306/book_shop?serverTimezone=GMT%2B8&useSSL=false";
            String username = "root";

            String password = "2651866367";
            conn = DriverManager.getConnection(url, username,password);
            // 3.通过Connection对象获取Statement对象
            stmt = conn.createStatement();
            // 4.使用Statement执行SQL语句
            String sql = "select * from books";
            rs = stmt.executeQuery(sql);
            // 5.操作ResultSet结果集
            System.out.println("bookId | title | authors | unitPrice | pubDate");
            while (rs.next()){
                int id = rs.getInt("bookId");// 通过列名获取指定字段的值
                String name = rs.getString("title");
                String ats = rs.getString("authors");
                String unit = rs.getString("unitPrice");
                Date pubDate = rs.getDate("pubDate");
                System.out.println(id +"   |  " +  name + "   |  " + ats +"   |  "+unit+"   |  "+pubDate);
            }
        } catch (ClassNotFoundException e){
            e.printStackTrace();
        } finally {
            // 6.回收数据库资源
            if (rs != null){
                try {
                    rs.close();
                }catch (SQLException e){
                    e.printStackTrace();
                }
                rs = null;
            }
            if (stmt != null){
                try {
                    stmt.close();
                } catch (SQLException e){
                    e.printStackTrace();
                }
                stmt = null;
            }
            if (conn != null){
                try {
                    conn.close();
                } catch (SQLException e){
                    e.printStackTrace();
                }
                conn = null;
            }
        }
    }
}
